fix: use local to precompute the condition

[hectorj2f]

When using the new logic serivce_account_email in https://github.com/chainguard-dev/mono/actions/runs/11401132104/job/31886045677?pr=20472#step:15:131, I got the following error 😢:

Error: Invalid count argument

  on .terraform/modules/package-update-check.package-update-check/modules/github-bots/main.tf line 2, in resource "google_service_account" "sa":
   2:   count        = var.service_account_email == "" ? 1 : 0

The "count" value depends on resource attributes that cannot be determined
until apply, so Terraform cannot predict how many instances will be created.
To work around this, use the -target argument to first apply only the
resources that the count depends on.

[hectorj2f]

I'm hoping someone can help me with this issue 🙏🏻 .

[hectorj2f]

It seems I am getting the same error regardless of these changes.

Error: Invalid count argument

  on ../../../../terraform/modules/chainguard/github-bots/main.tf line 6, in resource "google_service_account" "sa":
   6:   count        = local.create_service_account ? 1 : 0

The "count" value depends on resource attributes that cannot be determined
until apply, so Terraform cannot predict how many instances will be created.
To work around this, use the -target argument to first apply only the
resources that the count depends on.

I am closing this PR.